"Regrettably, I did in fact fail my most recent drug test and if I am asked, I am prepared to appear before judge Fox next week as a result.

"Substance abuse is a disease, which unfortunately doesn't go away over night. I am working hard to overcome it and am taking positive steps forward every day. I am testing every single day and doing what I must do to prevent any mishaps in the future.

Lindsay Lohan's Highs and Lows

"This was certainly a setback for me but I am taking responsibility for my actions and I'm prepared to face the consequences.
I am so thankful for the support of my fans, loved ones and immediate family, who understand that I am trying hard, but also that I am a work in progress, just as anyone else. I am keeping my faith, and I am hopeful....Thank you all!!!

A L.A. District Attorney spokesperson told TMZ -- the first to report news of LiLo’s alleged failed drug test -- that her office was not “officially notified” of the test results. No court hearing has been scheduled, Sandi Gibbons said.

Celebrities in Rehab

Earlier, Lohan had denied flunking any test. She told Usmagazine.com on Friday: "I'm fine." She also said of TMZ: "They're all nuts." Her lawyer, Ed MacPherson, had previoulsy told Us he "had no idea at this point whether or not there is any merit to this."

The 24-year-old “Mean Girls” star, who was released from rehab in August, flunked her drug test sometime last week, sources told the news outlets.

Lohan reportedly must serve 30 days in jail for a positive drug test, according the terms of her probation.

Child Stars Then and Now

The actress served 14 days of a 90-day jail sentence over the summer for violating the terms of her probation in a 2007 DUI case.

She was similarly released early from a 90-day rehab sentence after serving 23 days at UCLA Medical Center and must undergo twice weekly random drug tests.

In addition, Lohan was also ordered to:

undergo psychotherapy 4 times a week.

have a minimum of 7 contacts per week with a mentor of some kind - not a physician.